Saturday, October 15, 2005

Is it done?

If you want to put an end to dry fish, I have good news. Testing fish for doneness is really quite easy – dig in with a fork and look inside. So, check early and check often, and you are guaranteed mouthwatering fish every time.

The most important thing to remember is that the fish will continue to cook after it is off the heat, so you have to remove it before it is done to your liking. Here are some guidelines on how well to cook your fish and when to check it for doneness.

Step 1: Eye ball your fish to figure out how thick it is. No, you don’t need a ruler -- I just used it for the picture.

Step 2: Decide how well done you want your fish. Most fish taste best when they flake and are opaque. Two exceptions to this rule are tuna and the salmon family (salmon, steelhead trout and arctic char). They taste better on the rare side, when the center is still translucent.

Step 3: Estimate cooking time. Here is a rough guideline for well done fish. For translucent center, cook fish a few minutes shorter.

High heat (Broiling, grilling, steaming, pan frying)

Moderate heat (Baking at 425, poaching)

Fillets

8 min. per inch of thickness

10 min. per inch of thickness

Steaks

10 min. per inch of thickness

12 min. per inch of thickness

Small whole fish(1 Lb)

10 min.

14 min.

Medium whole fish(2.5 Lb)

14-17 min.

20-25 min.

Step 4: Cook the fish 2 minutes less than your estimated time, then check for doneness. You can always pop it back in the oven, but you can’t turn the clock back if you overcooked it.

Step 5: Check the fish for doneness by separating its flakes with a fork. Remember that the fish will continue to cook for another 5 minutes once it’s off the heat, so you want it to be slightly underdone when you take it off the heat.

Fish right off the heat

Fish after 5 minutes of resting

Fish Doneness FAQ

Q: Some parts of my fish are thicker than others. How do I estimate the thickness?A: Always measure your fillet or whole fish in the thickest part.

Q: Which part of the fish should I peek into when I test for doneness?
A: The thickest part.

Q: I can separate the flakes with a fork, but the fish looks wet inside. Is it undercooked?
A: If you can separate the flakes, your fish is cooked. Wet is good – it means it’s juicy.

Q: Is it safe to eat fish if the center is translucent?A: It is safe to eat salt water fish (such as salmon and tuna) with translucent center since they are not prone to parasites. But fresh water fish should be completely cooked through.

Q: If the fish is not done when I test it, how much longer should I cook it?A: After the estimated cooking time is up, check your fish every 2 minutes or even less if it’s close to being done.

Q: What if the fish doesn’t flake when I test it for doneness?A: Firm and dense fish, like striped bass, mahi-mahi, and swordfish do not flake easily. Be assertive when pulling the flakes apart. If you have to, make a small incision in the fish with a knife.

Q: What if I break the fish while testing it for doneness?
A: Don’t be afraid to break your fish. Fish flakes are like pieces of a puzzle – you can put them back together after separating them. If you are worried about the presentation of your dish, serve the broken piece to yourself and give your guests the pretty pieces. It’s always better to eat broken fish than dry fish.

Q: Why are some of my fish pieces came out more done than others?
A: If you cut a fish fillet into several pieces, some might end up thinner than others and should be taken off heat first. To avoid this, ask your fishmonger for the thick end of the fillet that has less variation in thickness.

Q: How do I check whole fish for doneness?A: To check the doneness of the whole fish, insert a knife between the backbone and the top fillet and try to lift it slightly off the bone. If the flesh does not want to separate from the bone, cook the fish a few minutes longer and check again.

It's not a stupid question. And the answer is -- you don't know. Once you are familiar with the species, you know if they are fresh or salt water (carp is fresh, bluefish is salt, etc), but some can be either fresh or salt (like catfish). You have to ask your fishmonger. If you live on either one of US coasts, pretty much everything you'll see in fish markets is salt water unless it's labeled as fresh water.

I grew up in catfish country and don't get enough of it here in CA. For some reason it's a bit of a maligned species out here. Too bad, it's their loss.

Question... you mentioned that there are both fresh water and salt water catfish. I seemed to remember that the saltwater catfish is not worth eating? Perhaps this is my own misplaced bias, but I can't recall ever seeing something sold as saltwater catfish.

I am not a good person to ask about catfish. We don't get much fresh water catfish in Boston, so I can't compare. The only type I've had recently was ocean catfish. It's not my favorite fish, but quite worth eating when pan-fried.

Most fish are considered "done" at 140F. This means you have to get them off the heat at 130F since the temperature continues to rise for another 5 minutes or so while they are resting. Tuna is best completely raw inside and just seared on the outside, so cook it for 2 minutes per side and call it done. Salmon is best warm and flaking, but still a bit translucent even after resting. If using a thermometer, take it off the heat at 110-120F (the temp will rise to 120-130F by the time you eat it).

I've never been a big fish fan. I've been trying to eat more health consciously though, and my local grocery store introduced me to this fantastic dry rub for salmon. Having never cooked it before I was a bit nervous. It came out perfect, and I thank you for it. Thanks a million!!!!! Eating healthy just got a whole lot easier.

What you say is true about wild salmon like coho and sockeye. They can indeed have parasites. The farm-raised salmon eats very controlled feed (making parasites extremely rare), and it's relatively safe to eat it raw without previously freezing. But cooking fish to even medium rare (translucent center) will weaken parasites significantly, making it almost impossible for them to survive in a human. So, that's how I (and most chefs) cook all types of salmon.

I was just scanning your page and noticed something that disagrees with the natural laws of the universe. You say that if you a remove the fish from the heat at 130 F, after 5 minutes it will be at 140 F. This may be a misconception- Yes, the fish will continue to cook internally because it is well insulated and holding the heat inside of itself (the fat molecules can not vibrate as fast and transmit the thermal energy to their neighbors as other things like metals or water can, Think of a thermos-between the water and the outer wall is a vacuum devoid of everything so that there is nothing to transmit thermal energy). Without any energy source, the only way or the temperature to go is down, it may take 5 minutes to lose an amount of energy reducing the fish to a temperature where cooking is not possible. If you have tested this and actually found that the fish increased in temperature, do not worry, you are not in the twilight zone or some parallel universe, you probably kept the fish in the pan, which continues to radiate heat for how long? 5 minutes. the metal pan loses heat very rapidly (is a good conductor) which enters the fish (now think of wearing a north face jacket in a room with the heat on). The fish's temperature rises because it can not lose heat as fast as the pan transmits it.

Here is how I understand residual heat. You remove the fish from a temp of about 450F, so it's surface is at about that temp. While the surface temp starts going down immediately, the temperature in the middle of the piece keeps going up since it's surrounded by higher temperatures. Whether it's 10 degrees or 5 degrees depends on the thickness of your piece of fish. But I don't think there is any dispute in the culinary community that the surface temperature goes down as internal temperature goes up.

hmm, sounds fishy. Your point about the internal temp going up because of the higher temperature on the surface of the fish, is logical because the surface of the fish is the heat source, and this is true. But when removed from the oven into a room of about 70F where will that heat source transmit most of its energy? To the center of the fish which has only a small difference in temp, or to the outside which may have a few hundred degrees of difference. It seems like the small amount of energy going inwards will be negligible because the surface is losing heat to the surroundings at a much faster rate. But like I said before, if this has been observed there must have been another heat source like a pan, tray etc. made out of a metal, in which case you have the winter jacket in a heated room scenario.

ok, if enough people have witnessed this happening, I guess I can't argue against it. Maybe it has something to do with the higher concentration of fat on the periphery of the meat which is repelling the thermal energy. Now that this thermal energy is trapped inside, it diffuses down its gradient from hot to cold, and the coldest area in the vicinity is the center.

Hi Wes...it's actually really simple, and it's referred to as carry over cooking. It's a scientifically established fact, and the denser and larger the object being cooked, the greater the degree of carry over cooking. Denser foods generally have a higher water content and therefore (because water has a higher heat capacity) the food continues cooking as the internal heat rises. Nothing fishy about it.

It depends how you define "done"? Technically, fish is "done" at 140F (removed from the heat at 135F). If you cook salmon to that temperature, it's a culinary disaster. I generally cook salmon that's good enough to eat raw (it's farm-raised, so parasites are not a problem, and fresh enough that bacteria is not a problem either). So I don't worry about it and cook it to very translucent (about 120F at the time of eating, which means removed from the heat at 115F). Doing this to wild salmon is a risk. It's worth it to me, but might not be worth it to you.

After years of shunning fish, I have recently decided to give it another try. My first attempt at cooking fish ended in an unmitigated disaster (dry and tasteless), as I am stumbling in the dark as to how long I should be cooking it. So coming across your blog is wonderful. Such great advice and tips, written from the viewpoint of someone who really loves fish. Thank you so much.

My husband has just been on a fishing trip to the Great Barrier Reef and returned with lots of delicious fish. I am not a confident cook when it comes to fish but after reading your blog feel much better and know where to come when I get stuck! I will be posting some of my attempts on my food blog http://apassionforfood-susy.blogspot.com/ so feel free to have a look. I have put a link to your blog.

Thanks for an insightful website. Had quite a laugh at some of the posts, which you so elequently replied back :-)Looks like it's been a while since the last comment. My concern is about the farmed raised salmon. Aren't they given tons of antibiotics due to being in such close quarters, disease is prevelant. Farm raised fish/salmon also contain 10 times more toxins (dangerously high levels of PCBs and dioxsin)....so I do stay only with wild caught salmon or eat the farm raised very, very rarely. Again, thanks for sharing all your great tips and

keep in mind that not all farm-raised salmon is created equal. you get what you pay for. go to Whole Foods, pay $15/lb for farm-raised salmon and you'll get a great product with no antibiotics and great taste. but if you want to pay $8/lb for farm-raised salmon at your local grocery store, there are no guarantees.

Quick question, when i use a fillet of salmon that has the skin covering one side of the fillet i really enjoy eating the skin. Would the fish be negatively be affected by heating it up temporarily to 150 degrees on the skin side to achieve a crispy skin or should I try to find another way to get a nice tasty skin?

150F is very low. Are you cooking it sous-vide or in a 150F oven? It's a fabulous way to cook fish, but you won't get crispy skin. You can try to crisp it up afterwords in the skillet, but once the skin is flabby, it might have a card time crisping up nicely.

Ummm Salmon.. Everytime I cook salmon, I use tin foil to wrap around my slab at 350.. Butter the bottom, so the skin does not stick. I add either some beer or this time I used a half shot of whisky and a little bit of water around the side. to aviod drying out your fish. add some seasoning and cover over. I let my fish cook until the skin starts to peel away with ease. I test my fish by removing a flake with a fork from the thickest part and see if the pink is even thru out the sample. Johnson.

it's definitely fine in terms of bacteria (if the center is 130F, the outside is definitely 160+, which would kill all bacteria). In terms of parasites, according to FDA, you need at least 140F to kill parasites (or is it 145F). AT that temp, the salmon doesn't taste good. 130F is as high as I would cook it. If it was previuosly frozen, you have nothing to worry about (freezing would kill parasites). If it wasn't, you might be taking a tiny-tiny risk.